Device for measuring time intervals.



W. H. PRATT. DEVIQEV FOR MBASURINGTIME INTERVALS.

APPLICATION FILED JAN. l5, 1908. 1,022,593. Patented Apr. 9, 1912,

2 SHEETS-SHEET 1,

loo loos @ooo- Z5. Witnesses: f IVeh-bom mk wmiamH p atb, 9 zum r @M W. H. PRATT.

DEVICE FOR MEASURING TIME I1\TTERVALS.l

APPLICATION YILEDJAN.15,1908. 1,022,593. f APatented Apr.9, 1912 2 SHEETS-SHEET 2.

Witnesses'. Inventor: William pf'bt oqttly UNI-TED sTATEs PATENT oir-Frou..

WILLIAM H. PRATT,

0F LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORK. Y

DEVICE FOR MIEASURINGy TIME INTERVALS.

Specication of Letters Patent.

Patented Apr. 9, 1912.

Application filed January 15, 1908. Serial No. 410,935.

' T0 all whom imag concern:

Be it known that I, WVILLIAM H. PRATT, a citizen of the United States, residing at Lynn, county ofA Essex, State of Massa: chusetts, have invented certain new and useful Imprm'ements in Devices for Measuring Time Intervals, of which the following is a specification.

MyA invention relates to devices for measuring time-intervals, and has'for an objectk the construction of an apparatus which will measure an interval of time with great precision.

Another object of my invention is the construction of an apparatus whereby an ooserver, who desires to know thc exact time during which a phenomenon or group of `phenomena which he is observing occurs,

may start and stop aregistering mechanism at the beginning and end of the period during which he desires to observe, and by com paring the record so obtained with a similar record automatically made by some timemeasuring device, such as a clock for an exact, known period of time,-this record being made substantially simultaneously with the record made by the observers ac tion, thus determine the exact time during which his observation has been taken.

Another object of my invention is the con* struction ot' suchan apparatus that it may be accurate, andreliable. A

lVhilemy invention may be used in many ways, it is more `especially applicable to that class voi observations wherein it may be desired t-o know the exact time which it takes for a recurrent phenomenon, such, for example, as the rotation of 'a 'shaft or pointer, to take place.

My invention is an improvement over A-the various well known chronograpliic means for measuring` intervals of time, since 1t dispenses withthe necessity ot' measuring uit records which are registered on paper or a similar material mounted on a drumand computing the length ofthe time interval,` and gives readings directly upon Aa register-ing 'mechanisnn Afrom which the lengthfof the interval can be quickly calcuy 11011 more rapid than a chronograph for lated. It thus fiirnishes ameans which 4is measuring a tiniefintervalf lposition tot l, l I. members 16,11111 '16meta9etwtrv1th @1112s.

For a bet-ter understanding of my invention, reference may be had to the accompanying drawings, in which- Figure 1 isa diagrammatic view of my entire time-measuring device; Fig. 2 is an elevation, partly in section, showing certain details of construction of portions ot' my device; Fig. 3 is a sectional view on the line 3 3 of Fig. 2, partially broken away for a clearer understanding, of certain details of my invention; and Fig. 4 is a plan view of another portion of the'apparatus which I employ.

Referring to Fig. 1, I have shown electric conductors 1-2, to which are c .inected by suitable connections an electric motorl 3, which may be cut into and out of circuit by a switch 4. To one end of the motor shaft I have shown a gear-wheel 3, which is meshed with two gears 32. These gears are attached by suitable shafting to magnetic clutches 5 and 6, which will be explained in detail more fully farther on in this specitication, but which, in general, consist of a portion which rotates with the revolving ears 82 a ortion whichi stationar andv a portion which may be made to rotate. These clutches, when energized by the electric current, drive registering gear-trains 7 and 8, which may be of any well known con struction, and whose object is to measure the number ot' rotations of the shafts to which the magnetic clutches are attached when-these clutches are energized. I have shown a starting key 9,which maybe pressed down by the observer, and which, when pressed down, makes contact with a contact memberl10. As soonv as contact is made electro-magnet 11', which operates a inagnetic switch, is energized byineans of a battery 12; the circuit beingiclosed through starting vlever 9, conductor 91, electromagnet 11, conductor 111, conductor 112, to battery 12, conductor 101, and conduct-ing member 10. As soon as magnet 11 is energized it pulls up the lever 13, which is pivoted in any suitable fashion to a fined support by at shown in thefligure, contact ulled up, -ojis in the reverse,

member 101 and "clips 171 energizes members and 171. yllhe contact made by contact C1 of magnetic clutch 6', and thus causes. dial-train 8 to be set in motion. The circuit beingl made by closing clips 171 is conductor 101, conductor 101, brush ifi, .brush lf, conductor 171, clips 171, conductor 111, conductor 111, and battery 121. brushes i 13 make contact with the revolving portion of the magnetic clutch through suitable slip-rings whose construction is described more in detail with reference to Fig. 2. l have. shown a clock 18 ich has a pendu, lum 19, of any well kno i type, to the lower' extremity of which is attached a perinanent magnet 20, Suitabiy placed below the path et magnet 20, 1 have shown a Contact deyice which consists of two armatures 21 and 22 attached to certain spring` members f3-21, member 23 carryin` a spring-contact: 25, and member 21 carrying a contact-screw Normally, the Contact between members and 2G is not made, but upon the passage of' the pendulum bearing;I the permanent magnet or lr the armatures 21 and 22, these armatures are broughtl together by the mutual attraction of the armatures due 'to the flux induced in them by the magnet., and contact is made between the spring and screw 20. I prefer to place the contact device so that it will be under the influence ot the permanent magnet attached to the pendulum at the middle position ot the swing of the pendulum, but it may be placed atany suitable portion of the pendulums swing. .Vhile l have described a contact-making device of a certain character, I do not limit myself to this device, but may use any contact-making device of such a character that it can be operated at exact and known intervals of time. Ritter registering-train 8 has been set in motion by the observer, the tirs' Aswing` of pendulum 10 will cause members and to make cont-ait, and thus energize relay 27. TWhen relay 27 is ener- Igized, armature 28 will be attracted toward it, and thus a conducting portion of it makes Contact with a contact member 271, thereby energizing magnet 31; the circuit. being made through conductor 281, clip 17, clip '20, magnet fzll, conductor i321, conductor 111,

battery 12, conductor 10B, contact member 271. ll'hen magnet. 5l] is energized, it will pull down lei'er 30, which is similar in con-- .struction to lever 13 previously described, except that 1t nas three contact devices on its lower side` in place of the two which are on lever Upon a change in position of lever 30 from that shown in the figure, clips v32 are connectedtogether, wherfby rotating member 51 of clutch is energized, and registeringtrain 7 is set in motion, the circuit being, made through clip 32, conductor 321,brush E, brush Dfconductor 101, conbers similar to members 16 and 161.

ductor 101, battery 12, conductor 112 and conductor Simultaneously, with the ener-` gizing of clutch member ,51, lever 30, through closing clips-33, makes a circuit whereby magnet 31 of a time-counting device T, which will be described more in detail later, is energized periodically by the passage of magnet over armatures 21 and 22 and the action of relay 27; the circuit being` member 28, conductor 281, conductor 3111, magnet 3&1, conductor 331, clips 33, conductor 321, conductor 112, battery 12, conductor 10B, contact member 271. registering trains 7 and 8 are now being revolved by motor 8, and so continue until the observer has iinished his observation, and "ishes Ato tind the exact time which has elapsed since he started his observation. In order to do tnis he presses the stopping key against contact 'member 10. This causes magnet 3G, which is directly opposed in its operation to magnet 11, to be energized, and to pull lever 13 into the position shown in the figure: thus breaking contact between 'elias 17 and 171, and makinflr Contact bei f 2D tween clips 37 and 38, through contact mem- Then clips 171 are open-circuited, rotating magnet 61 ot clutch 6 is denergized, and at the same time stationary magnet 61 is ergized when circuity is made through clips 37, and 'thus in a manner to be described later, registering train 8 is vinstantly ln'ought to rest, as magnet (31 acts as a brake. The circuit made in this case is clips 37, conductor C, magnet G1, conductor C, conductor 101, conductor 101, battery 12,Y conductor 112. As soon after key is brought into Contact with Contact member 10, as magnet 20 passes over armatures 21 and 22, and contact between members and 26,is made, magnet '10 is energized, thus pulling lever 30 into the position shown in the ligure; circuit being` made through clips 38, conductor 281, member 28, member 271, conductor 10D, battery 12, conductor 111, conductor 111, magnet s' 0, clips 39 and conductor 381. lVhen lever has been pulled up in the position shown in the figure and made contactI between clips 29 and 11, rotatingr member 51 of clutch 5 is denergized, and stationary member 51 is energized, thus acting as a brake, and stopping registering train 7` instantaneously, as Will be explain d later in this speciiication. Registering"train 8 has lthus registered the number of revolutions occurring between the interval of pressingr the starting key 9 and the stopping key 35,- that to say, duringthe time ot the obser- -ration and registering train 7 has thus which will be described later.

pendi'll'um. The exact time then of the observation will be the iatio between the read-` ings ofl the registering train 8 and registering train 7 multiplied by the number of seconds during which registering train 7 has been. in operation; this numberl being counted on the time-counting mechanism T, This ratio will be correct in case gear-wheels 32 have both the same number of teeth. In case,

- however, for any desired reason, one gearfashion.

wheel is made. witha different number of teeth than another, and thus will make a dilferent number of rotations from the other, a suitable correction must be made. It will be obvious that while I have shown an electric motor geared to two driving shaftsany motor and any method of drivw ing the two shafts may be employed. l have shown resistances R in shunt with the various magnets to prevent-sparking.

Referring now to Fig. 2, which shows in detail the construction of the magnetic clutches, I have shown two supporting plates 42aud 43, which are connected and held apart by posts Between these plates -are magnetic clutches 5 and (i, clutch 5 beingl shown in section, both clutches being of a similar construction. 46 is a rotatable shaft:l connected to gear-wheel 32, so that it will be turned by the action of motor 8.

.Supportedupon this shaft is an electromagnet 47', which is immovably connected'to the shaft by a set-screw 48. Mounted upon magnet 47, and suitably insulated in any Well known fashion, are collector-rings 49 which make` contact with suitable brushes, one of which, B, I have shown on clutch 6. These collector-rings are connected to the terminals of magnet 47 in the well known An adjustable friction-cap 50 is shown surroui'iding the end of magnet 47, and retained in position by means of locknut 51. Cooperating with rotatable magnet 47,1 have shown the stationary magnet 52, which is held rigidly to plate 42 by means of clamp 53, screws 54 and shoulder 55. An adjustable friction-cap 56, with its lock-nut 57, both similar to the cap and nutfor magvnet 47, are provided for this magnet also. Drilled in the magnet 5.2 is a hole 58, which is adapted to receive shaft), which is supported by the portion of magnet 52 and plate 6l of; registering dial 7. On one eX- tremity of shaft 59-is a'disk Aof magnetic material 62 faced on both sides with some non-magnetic material 63, such as leather. At 'the opposite extremity of shaft 59 is mounteda driving-pinion 64, which meshes with gear, 65 of the registering train-` 7 fin the well known fashion. This pinion 04is made with teeth ',of suitablewidth of face, gothat shaft,59 maybe moved longltudinallya suitable. dgtancqjwithfr getting the teeth absolutely prevent any such motion. AftenA the observer has pressed the starting key, and thus caused the circuit of magnet 47 to be made, as previously described, by the clock pendulum, and magnetically operated switch 30, circuit of magnet 52 is opened and magnet 47 is energized, disk ($2 is then pulled toward revolving magnet 47, and through magnetic force, made to revolve with shaft 4G. This causes the registering train to be set in Vmotion in the previously described fashion. `Vhen the observe-r desires to stop the movement of the registering tain, so as to obtain the time vof his oliservation, in the manner previously described, rotating lnagnet 47 is deenergized, and stationary magnet- 52 is energized. This causes disk 62 to be attracted in a reverse direction from that previously described, and thus by magnetic force to be held in a fixed position against friction-cap 5G. This causes the registering train to be stopped at once, as disk 62 acts as a magnetic brake, and hence thc` exact number of revolutions of shaft 46 will be registered. It will be understood that magnetic clutch G is similar in its action vand construction/t0 clutch 5, altl'iough the operation of making and breaking its various circuits. as previously described', is slightly dissimilar to that used in connection with clutch 5. It will also be understood that, While I have described a certain form of clutclnI do not limit myself t'o this particular construction; but may employ any form of clutch which will give the results that I .may obtain by the form of clutch described.

.Mounted on plate 42, and below themagnetic clutches, I have shown the time-counting mechanism, which is in its essential features a .clock-work mechanism actuated by the action of pendulum 19, and register.-

`ing every time the magnet 20 passes over a vonds,:and the smaller dial geared to it, and

registering minuteslin vthe well known fashion. Itis obvious that any form of countmg mechanism,which 1s desired, may be 'employed for this purpose. Referring to Fig; 2 wl1ich shows the elevation of the coi'mting meeliaansni,-` I have show-n` platespu-stil'an'd `dial 68 connected 'by posts 69 fand @nndjsecured to plate ,42 .bymeans brackets 7l and 72. Betering non? to lili 3, I have shoivn magnet Sil attached to 70, post being shown in Fig. 2, ln

o, o, post con secured by a pivot to plate 6G.

held in a dovvnward position b;

the spring 77, ivhich is rod '78 'and by means et' the adjusting nut 79, held against a post '7.1

the ivell known fashion. Gn the. letter edge of lever 76 is a vl-shaped projeeti -:V winch coperates vvith the star-Wheel Sl.,

that is mounted on shaft SQ. lifoun ed on shaft 82 is also a ratchet-'whee with which ratchet Sli on lever coop There is also a spring-pressed pa, i mounted on plate 66, which cooperates witn ratchet-vvheel 83, and prevents any backA Ward movement of this ratchet-wheel when' ratchet SLL is disengaged trom said "ivl'iei"v rlhe operation of this time-countingI dei ieeis as follows: As previously descriifed, net 34 is intermittemily energized by movement of the clock pendulum. Armature 74 is then lifted, and '-.vith it lever 1.o and ratchet Se are raised. Ratchet Si then drops into mesh with the tooth behind that with which it was previously engaged, and upon*y a denergization o'j magnet 3i the loiver end of lever 76 is pulled down by the action of spring 77, and thus the ratchet-- Wheel is caused to rotate approximately the space of' one. tooth. ln order to insure a uniform travel ot' one tooth, the il-shaped projection 8O on lever T6 employed, as this Will cause the ratchet-wheel and the shaft to revolve a space of one tooth exactly, since in its downward position it meshes-With the star-Wheel, and thus causes a uniform rotation of this wheel, and hence the measuring` pointer. Paul S5 prevents any backward movement ot' the wheel. .ln order to provide for a resetting et the pointers, and also of the pointers on registering trains 7 and 8, a resetting device is provided, as olloivs', the device not being shoivn for trains T 8. As shown in Figi'. 3, spring-pressed pa'ivls 8G and 87 are in their normal position against the vertical spring S8. Member S8 is rigidly secured to the resetting lever S9, which has Jformed in it guide S91 operatingin conjunction with supporting and guiding screws 90. Lever 89 is held in its outivard position by means ot spring 91. Mounted lupon the pointer shat'ts are heart-shaped cams 99 and 93, which are flexibly connected to the shafts by means of springs 94. ln order to operate this device, lever; S9 is pressed, which causes members and 96 or" pawls 86 and 87, respectively, to engage against the cams 92 and 93, and thus causes Athem to rotate and return the indicating and i eerder, 3 a i Y 0nd,. or beat, behi marked on the dial. cai-e ot the fractional which occurs operator has pendulum n presse@ pa s position, Y the .pendulum ov which will occur vii Y one i device cui 3 and i to which are fnie'inbers )l and and. iso spring and adjustable contact screvir @hiring members 23 and 2st are secured to member 198 by means of binding-posts 10,1. and 10Q, which serre as terminals 'tor ctmnectin,g Vthe necessary conductors to the contact members 25 and 26. Suitable adjusting; screws 103 and 10st, and stops 105 and 10G, which may be adjusted, are provided, as Well longitudinal adjusting screw 10.7, and vertical adjustingscrew 199. The operation oiC my device is as follows: lilien an observer desires to measure the ei:- act time which elapses duringIr his observation ot any phenomenon7 or group of phenomena, he presses the startingl key ot the mechanism, which, as previously described, causes a registering train to 'bc set in motion by an electric motor. Directly after this a clock-Work mechanism causes a second refr tering; train to be set in motion by the same electric motor. ri`he observer then, upon the conclusion o'f his observation, presses the stopping;` key, which immediately stops the registering train, which he has himself set i by the starting' lrcy, and upon the in motion next passage ot the pendulum over a predetermined point, the registering,- train, set in motion by the pendulum, is stopped also. The registering train set in motion by the clock-work mechanism Willthen register a certain number ot revolutions for an integral tion. By taking the ratio of these and comparing them with the exact. number of time unit's lrecorded by the time-recorder, the exact length of time taken for the observation will be found with an accuracy which very great. 'y

I do not desi-re to limitmyseli to the par ticular construction and arrangement of parts here shown, since changes, which do noti depart `from the spirit ot my invention, and which yare within the scope of the present claims, will be obvious to those skilled in the art. I

lVhat claim as new and desire to secure byLetters Patent of the United States, is:

1. The method of measuring an interval .of time consisting in comparing the registra- .tion ot a device registering during that 1nterval of time with the registration of a substantially similar device registering an exact interval et time ot substantially the same length as the interval whose length is to be r measured, and by comparison of the two registrations determining the length of the interval to be measured.

Q. The methodof measuring an interval of time consisting in comparing the registration of a device registering during that in terval oit time with the registration of a sub- .\-;t=.mtially similar device registering an intcrval of time of substantially the same lcngtl'i as the interval to be measured, regisltering during substantially the same period,

. and registering only for anintegral number et time-units, and by comparison of the two registrations determining the length of the inte val to be measured.

S. r,lhemethotl of measuring an interval of time consisting in employing a device registering for an intervaliot time whose length it is desired to measur/e` a second substantially similar' device registering an interval oi time ot substantially the same length, and

only rcaistering for an integral number of tiine-mums7 and by comparison of the registration of the two devices computing the exact length of the time-interval to be measnrefl. y

The method of measuring an interval of time consisting in employing a device which caribe made to registe. :lui-ing said interval, a second substantially similar' device automatically registering a time-interval, of an integral number of time-units, of substantially the same length as the interval to be measured and occurring during substantially the same period, and by comparison and computation determining the exact length of the time-interval to be measured.

5'.The method of measuring an interval of time consisting in employing a registering device which can be started yand stopped at the beginning andz end of said interval -respeetively, a second and substantially similar registering device automatically started and stopped at a time-point nearest to and next succeeding that at which the first device is started and stopped, and by comparison ot the registration of the tivo devices and com# putation with the number of time-units duly` ing which the second device registers determining the .length of the interval ottime to be measured.

x6. The method ot' measuring an interval of time consisting in employing a registering device which can beA manually started and stopped at the beginning and end of said interval respectively, a second and substantially similar registering device automati cally started and stopped by a clock-work mechanism at a point predetermined by the mechanism nearest to and next succeeding that at which the rst device is started and stopped, and by comparison of the registration of the two devices and computation with the number of time-units during which the second device registers determining the length of the interval of time to 'be meas nred; 'f' 7,V The method of measuring an linterval of time consisting in employing a register ing device which can be manually started vand stopped at the beginning and end of .ing device which can be started and stopped at the beginning and end of said interval respectively, it second and substantially similar registering device automatically started and stopped by a time-pendulum operating means and by comparison of the registration of the two devices and computation with thenumber of time units during which the second device registers determining the length of the interval of time to bel measured.

9. The method of measuring an interval ot time consisting in employing a registering device which can be started and stopped at the. beginning and end of said interval respectively, a second and substantially similar registering Adevice automatically started and stepped by a time-pendulum operating *i means at a predetermined point in the swing ot the' pendulum immediately succeeding starting of the first device and stopped by the. pendulums operating means at the -same point of its swing immediately succeeding the stopping of the first device, a time-counting device actuated by thetimevas pendulum operating means counting the. time orp registration of the second registering 'device and by comparison ot the registrar tion of the two devices and computation with the number of time-units counted by the time-counting device determining the length of the interval of time to be measured.

10.".i`he method et measuring time-intervals consisting in employing a device registering the interval of time to be measured, a second and substantially similar device automatically registering for the integral number of time-units nearest to thatI of the time-interval to be measured and by comparison of the two registrations and computation with the number of time-units through which the second device registers determining the length at the interval et time to be measured.

1l. An apparatus for the measurement of time-intervals comprising a registering de.- vice and meanstor causing the same to register during the interval ot time to be measured in combination with a second registering device tor comparing the registration ot said lirst mentioned device, and means :tor causing said second registering device to register for an integral number ot time-units.

122m apparatus tor the measurement of time-intervals comprising a registering device and means tor causing the same to register during the interval of time to be measured in combination with a second. registeringdevice and means for'causing the same to register t'oran integral number of time-units nearest to the length of the time-interval whose length is to be meas ured.

13. An apparatus tor the measurement. ot

time-intervals compr' a registering device, means tor causing tnesame. to regista during the interval oi time to be measured,

a second registering device whose rate oi registration bears a constant and known relation to the rate of registration of the first mentioned device, means for causing the second mentioned device to register for an integral number of time-units, and a device torcoiinting the number of time-units during which said second registering device registers.

14. An apparatus for tlie measurement et time-intervals comprising a registering device, means for causing the, same to register during the interval of time'to be measured, a second and substantially similar device, a

f time-marking means, and means in operative relation therewith for causing the second device to register for an integral number of time-units- 15. An apparatus for the measurement ot' time intervals comprising a registering de- ,vice, means for causing the same to register ineaaee during vthe interval ot time to be measured,

a second and substantially similar device, a clockwork means, and means in operative relation therewith for causing said second device to start and stop registering for an integral number ot time-units.

i6. in apparatus for the measurement ot time-intervals comprising a registering device, means for causing the same to register during the interval of time to be measured, a second and substantially similar device, a time-pendultim, means in operative relation therewith Vtor causing the second device to automatically register Jroi` an integrai number ot time units, and a device tor counting the number of time-units during which the second registering device registers.

17. n apparatus for the measurement oit time' ervals comprising a registering device, means tor causing the same to register during the interval ot time to be measured, a second and substantialljiT similar device, a seconds pendulum, and means-in operative relation therewith for causing the second device to automatically register for an e:\:- act number of seconds.

18. An apparatus for the measurement ot time-intervals comprising a registering device, means tor causing thesame `to register onds pendulum, a means in operative relation therewith for causing the second device to automatically' register for an exact num` bei' of seconds, and adevice for counting the number of seconds curing which the second registering device registers.

' 19. rin apparatus tor the measurement oif time-intervals comprising a registering device, means tor causing the saine to reu-'ster during the interval. ot time to be measured, second and siibstantialiy similar device, a time-pendulum, and means in operative relation therewith for causing said secondv device to start and stop re,n ering at a fixed point of the pendulum@ swing.

20. An apparatus tor the measurement et inie intervals comprising a registeringr device, means toi; causing the same to register during the interval ot time to be measured, a second and substantiaily similar device, a time-pendulum, means iii operative relation therewith toi" causing said second device to start and stop registering at a lined point of the pendulums swing, and a tiine-couut ing means counting the number ot pendulum swings. l

2l. An apparatus for the measurement of time-intervals comprising a registering device, means Jfor causing the same to start and stop registering at the beginning and end of said interval respectively, a second device substantially similar to the first device, a'clockwoilr means, and means in onerative relation therewith for causing the second device to start and stop registering.-

and stop registering at tlieibeginning andend of said interval respectively, a second device substantially similar to the first device, a time-pendulum, means in operative relation therewith for causing the second device to start and'stop registering, and a time-counting means counting the time dur- -iihigun'hich the second registering devicek registers.

23. An apparatus for the measurement of intervals comprising a registering dev-ice, means manually operative for causing the same to start and stop registering at the beginning and end of said interval respectively, a second and substantially similar device, means tor causing the same to automatically register during an integral number of exact time-units, starting' and-stop ping itat the exact time-.point immediately succeeding the time at which the Iirstdevice is started and stopped, respectively.

24. VAn apparatus for the measurement of time-intervals comprising a registering device, means manually operative for causing the same to start l stop registering at the beginning and t f saidl interval respectively, and a secc, `nd substantially similar device automatically made to register' during .the integral nui'i'ibcr of exact timet the length of the time-interval 'to be measured, or me .ning Atime-intervals for causing a registering i', and a second means causing a second a substantially similar device to register for an integral number of exact time-units, the second means being so interconnected witn the first as to cause the secstartand stop registering" at predetermiu "ic-points immediately `ceeding the .i ing and stopping points, respectively, or" the iirst device.

26. In combinatiomtwo substantially similar registering devices, means for driving these devices, means for starting and stopping one device, and means interconnected with the secontl 'means Afor starting and stopping the second device. i

27. In combination, two substantially simicomprising device to regi means for connecting each device to the registering source, manually actuated means for-actuating one connecting means, a clockwork mechanisiii'and means operated by the clockwork mechanism for actuating the other connecting means.

. 28. In combination, two substantially7 similarA registering devices, a registering source, means forconnecting each device to the registering source, manually-actuated means for lar registering devices, a registering ,.soiiice,w

actuating one connecting means, a clockwork.

'mechanism andl means operated'by the clocklar registering devices, a registering source,

means for connecting each device to the registering source, manually-actuated means for actuating one connecting means, a clockwork mechanism, means operated by the clockwork mechanism for actuating the other connecting means for an integral number of exact tune-units, and a device for counting the number of time-units during which the clockwork mechanism actuated registering device registers.

Si. ln combination, two substantially. similar registering devices, a registering source, means -for connecting each device to the registering source, manu ally-actuated means for actuating one connectin(T means, a clockwork mechanism, and means interconnected with the manually-operatcd means and actuated by the clockwork mechanism for actuatingl the other connecting means for the integral number ot exact time-units nearest the number during which the first connecting means is actuated.

32.- The combination, in an apparatus for measuring time intervals, ot an operating source, two substantially.similar registering devices which may be connected to the source, and means ilor connecting and disconnecting one ot said devices with said source at the beginning and end of the interval to be measured, a clockwork mechanism, and means actuated by the clockwork mechanism for connecting and disconnecting the second registering device trom the source at points .predetermined by1 the clockwork mechanism.

33. The combinati onL in a device for measuringtime-inteilvals, of an operating source, two substantially similar registering devices which may be independently connected to the source, means for connecting and disconnecting one of said devices with said source at the beginning and` end et the interval to be measured, a clockwork mechanism and means interconnected with the first means and actuated by the clockwork mechanism for connecting and disconnecting the second registering device from the source 'at points predetermined by the clockwork mechanism andx immediately succeeding respectively the rua ` nccting and disconnecting the second registering device from .the souice at points predetermined by the clockwork mechanism and immediately succeeding res ectivel the time at which the first registering device is connected and disconnected, and a time'- counting device for counting the number of' time-units during which .the second registering device is caused to register.

The combination, in a device for measuring time-intervals, ot an operating source, two substantially similar registering devices which may be independently connected to the source, means for connecting each of said devices to the operating source and tor disconnecting the Same so as lto bring the moving parts ot the registering devices instantiy to rest, means tor actuating one of said connecting and disconnecting means, a

` clockwork means for actuating the second or" IAT- said connecting and disconnecting means. and so connected thatit causes the second registering device to only register for an in tegral number ot exact time-units.

36. The combination, in a device for measuring time-intervals, of an operating source,

' tivo substantially similai registering devices which may be independently connected to the source, means tor connecting each ot said devices to the operating source and tor disconnecting the same as to bring the moving -parts ot the registering devices instantly to rest, means for actuating one ot said connecting and disconnecting` means, a time-pendulum, means in operative relation to actuating means on the timependnlum during a portion ot the pendulnms swing tor actuating the second of said connecting and disconnecting means and so connecting that it cans s the second registering device .to only register .tor an integral number of exact timeainits, and a tune-counting device tor counting the number .ot time-units during which'the second registering device registers.

ci. The combination, in a device toi' regis- ,tering tiniein'teivals, of an operating source, Atwo substai'itially similar registering devices which may be independently connected to the source, means for connecting each of i saiddevices to the operating source and tor 'disconnecting the same soasto bring the moving parts of the registering devices in stantly to rest, means for actuating one of said connecting and disconnecting means,

time-pendulum, and means in operative lation to actuating means on the time-peli.- duluni during a portion of the vpcndulunis swing so as tocause the second registering device to start registering when the pendu lum first passes the operative portion of its swing after the first registering device has been started registering and to stop registering when the pendulum irst passes over the operative portion otits swing after the second devicehas been stopped registerin.

38. The combination, in a device for registering time-intervals, of an operating source, two substantially similar registering devices which may be independently connected to the source, means for connecting each of said devices to the operating source and for dis connecting the same so as to bring the moving. parte of the registering devices instantlyhto rest, means for actuating one of said connecting and disconnecting means, a time-pendulum, means in operative relation'v to actuating means on the time-pendulum during a portion of the pendulums swing go as to vcause rthe second registering device .to start registering when the pendulum first passes the operative position' of its swing after the first registering device has been started registering and .to stop registering when the pendulum first passes ,over the operative position of its swing after the second device has been stopped registering, and a' time-counting device for counting the number or" time-units during which the second registering device registers.

39. The combination, in `a device for measuring time-intervals, of a motordriving two shafts, two substantially similar revolution counting devices for counting the number of revolutions of each shaft, means toi' connecting and disconnecting each device to a shaft, means for actuating one of said connecting and disconnecting means, a clockwork mechanism, andmeans actuated by the clockwork mechanism for actuating the other connecting and V disconnecting means.

40. The combination, in a device for ineansuring time-intervals, of a. motor driving two shafts, two substantially similar revolution counting devices for counting the number of revolutions oit each shaft, a clutch mechanism for connecting each device to a shatt, means for actuating one 'of said clutches, a clockwork mechanism, and means, in operative relation therewith for actuating the second clutch. i

41. The combination, in a device for. measuring time-intervals, of a motor driving two shafts, two substantially similar revolution count-ing devices for counting theA number of revolutions ot each shaft; clutch lio mechanisms for connecting each device to a shaft, means for ,actuating one of said clutches, a clockwork mechanism, and means in operative relation therewith for operating the second clutch and so interconnected 'with the first clutch-actuating means that it will only actuate its clutch after the rst clutch has been actuated.

42. The combination, in a device for measuring time-intervals, of a motor driving two shafts, two substantially similar revolution counting devices for counting the number of revolutions of each shaft, clutch mechanism for connecting each device to. a

shaft, means for actuating one of saidv clutches, a clockwork mechanism, and means in operative relation therewith for causing the second clutch to operate for an integral number of exact time-units.

43. The combination, in a device for measuring time-intervals, of a motor driv' `:it will eausethe second clutch to be actuated for the integral number of exact timeunits nearest the number'for which the first clutch is actuated, and a time-counting mechanism for counting the number of timeunits during which the second clutch is ac tuated. y f

44. The combination,y inV a `device for measuring time-intervals, of a motor driving two shafts, two substantially similar revolution counting devices, electromagnetic means for independently connecting the revolution counting devices respectively to the shaft, means for operating one of the' electromagnetic means, a' clockwork mechanism,'and a `second means operated by the clockwork mechanism for operating the second of said electromagnetic means.

45. The combination, in a device for measuring time-intervals, of a motor driving two shafts, two substantially similar revolution counting devices, electromagnetic means for independently connecting the revolution counting devices respectively to tlieshafts, means for operating one of the electromagnetic means, a time pendulum means in operative relation therewith, and a means in operative relation with said means for performing the same operations on the second electromagnetic means as have been performed upon the first electromagnetic means at points` predetermined by the pendulum-actuating means and immediately after they have been performed upon the rst'electromagnetic means.

ytering devices to'the,shat'ts and discern en number of revolutions of thesha .is

"means in operative relation therewith controlling the other of said relays in ldevices alternately, means for controlling 46. The combination, in a t'iinednterval measuring apparatus, o't an electric moti i driving two shafts, two substantielljj,r simi i registering devices for registering the num ber of revolutions oi the shafts, electricA operated clutches for connecting the reg.

ing the same from the shafts, electricn operated relays operating said chit means for operating one of said clockwork mechanism, and means op by the clockwork mechanism for operating the other relay.

cra t ed measuring apparatus, ot an electric moor driving two shafts, two substantially r lar registering devices ttor registering i; number of revolutions of the shafts, ele@ trical1yoperated clutches for eonnectiii registering devices to the shafts and t connecting the saine from. the shafts, elem trically-operated relays operating s clutches, means for operating one et sa. relays, a' time-pendulum, and means erative relation therewith tor operatingy second relay so that the registering de ,g which it controls registers for an integral number of exact time-units.

48. The combination, in a time-interval measuring apparatus, ot an elect ic driving two shafts, two substantial lar registering devices for registe trically-operated clutches for connecti registering devices to the shatts, e cally-operated braking devices for the registering devices to stop' in ously when they are disconnected revolving shafts, and electiically-operatcil relays 'for operating the clutches or brak' devices alternately, means for controll. one of said relays, a times-pendulum,

o; i 'he rel -ber of revolutions of the shafts, electrically'- operated clutches for connecting the regis tering devices to the shafts, electricallyoperating braking devices for causing the registering devices to stop instantaneously when they are disconnected troni the revolving shafts, and electrically-operated re'- lays for operatingthe clutches orfbraking one of said relays, a time pendulum, and inc-ans in operative relation therewith for controlling the other of said relays, the rclny circuits being so interconnected that the pendulum-operated clutch and braking devices can only be operated after the other `clutch and 'braking devices` have been operated and the clutch isoperated for the ti1neperiod covering the integral number of exact time-units nearest that through which the first, clutch operates, and e device for counting the time of operation of the 11min olutclrnctuated by the time-pendulum actuating means.

In 'witness whereof, I have hereunto set 15 my hand this' thirteenth day of January, 1908.

WILLIAM H. PRATT.

Witnesses JOHN A. MGMANUS, Jr., CHARLES A. BARN/mo. 

